The invention discloses a method for returning and sampling a polymer solution in a bottom hole. The method comprises the following steps of: inserting a continuous oil pipe into an oil pipe; compressing nitrogen by using a nitrogen pump, and introducing the compressed nitrogen into the continuous oil pipe; and allowing the nitrogen to pass through the continuous oil pipe and enter the oil pipe, and discharging the polymer solution, which is above the end part of the continuous oil pipe, in the oil pipe. By the method for returning and sampling the polymer solution in the bottom hole, the polymer solution entering a stratum through a blasthole can be obtained, and after the viscosity and concentration of the solution are understood, a condition of mechanical shear degradation of the polymer solution after the polymer solution enters the stratum through the blasthole can be understood, which is important for recognizing the viscosity of the actual working fluid of the polymer solution.